Republican presidential candidate Donald Trump stops and turns to the press as he greets the crowd after speaking at a campaign event at the Valdosta State University in Georgia on Feb. 29. (Jabin Botsford/The Washington Post)

This is the second of three posts describing how political science helps explain the success of Donald Trump. In the first post, we discussed the research showing that most voters are not ideologues, and, in particular, that many Republicans have liberal positions about government spending. This gives a heterodox candidate like Trump an opening.

This post describes the research underlying another key aspect of Trump’s appeal: the grievances of some white Americans and their hostility to minority groups.

Along with demonstrating that most Americans do not organize their political opinions based on ideology, Phillip Converse’s field-defining 1964 essay argued that Americans do organize their opinions around something else: attitudes toward social groups.

Their influence on mass politics became stronger in the 1960s and 1970s. As the Democratic and Republican parties took divergent stands on civil rights, attitudes toward blacks became a powerful predictor of which party Americans identified with. Attitudes about African-Americans are a majorreason why the once solidly Democratic South has become a Republican stronghold.

Barack Obama’s presidency has made attitudes about race matter even more. There is now an enormous gulf between Democrats and Republicans in how they react to race-related events, such as the deaths of Trayvon Martin, Michael Brown, Eric Garner, and Freddie Gray. Democrats and Republicans were even divided over Beyonce’s Super Bowl halftime show, with Republicans nearly 50 points more likely than Democrats to disapprove of her tribute to the Black Panthers.

Vanderbilt political scientists Marc Hetherington and Drew Engelhardt showed last week just how much more racially conservative Republicans have become in recent years. They concluded from those findings that “it is not surprising that a candidate (Trump) who is well known for questioning President Obama’s citizenship…and said that black youths have ‘never done more poorly’ because ‘there’s no spirit’ would be attractive to a party that these days is dripping with racial resentment.”

But Trump is not only tapping into negative attitudes about minority groups. Many have suggested that Trump is appealing to white nationalistic fears of an increasingly non-white America. His candidacy, they point out, has garnered support from people like former Ku Klux Klan leader David Duke, who told his followers last week that voting against Trump “is really treason to your heritage.”

Analysis Includes white Republicans and pure independents. Numbers at the bottom of the displays represent the sample size for each point.

These graphs show that white independents and Republicans who think their identity as whites is extremely important are more than 30 points more likely to support Trump than those who think their racial identity is not important.

Likewise, white Americans who perceive a great deal of discrimination against their race are almost 40 points more likely to support Trump than those who don’t think whites face any discrimination.

And whites who think it’s extremely likely that “many whites are unable to find a job because employers are hiring minorities instead” are over 50 points more likely to support Trump than those who think it’s unlikely that many whites are losing jobs to minorities.

These findings are consistent with the important research of Duke political scientist Ashley Jardina, who wrote some of the survey questions used above. Her research shows that white identity more strongly affects opinions when whites perceive themselves as under threat. This foreshadows a rising white identity politics as the United States becomes a majority-minority nation.

In sum, Trump’s “us against them” campaign resonates in an American political environment that has long been centered on social groups and has grown even more so in the Obama era. Both white identity and hostility toward minority groups are propelling Trump — perhaps even to the nomination.

Michael Tesler is assistant professor of political science at UC Irvine, co-author of “Obama’s Race” and author of the forthcoming “Post-Racial or Most-Racial? Race and Politics in the Obama Era.”

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